#app{
    width: 20rem;
    background-color: bisque;
    padding: auto;
    margin: auto;
}
button{
    border-radius: 45%;
}
.btn{
background-color: yellow;
}
.btn1{
    background-color: red;
    color: aliceblue;
}
.btn2{
    background-color: green;
    color: aliceblue;
}